Apparatus for producing anhydrous ethyl alcohol directly from mashes and the like



A. GORHAN Feb. 5, 1934.

APPARATUS FOR PRODUCING AHHYDROUS ETHYL ALCOHOL DI RECTLY FROM MASHESAND THE LIKE Filed June 14, 1952 Patented Feb. 6, 1934 PATENT OFFICEAPPARATUS Foa PRODUCING ANHYDROUS ETHYL ALCOHOL DIRECTLY F R O M MASHESAND THE LIKE Adolf Gorhan, Liesing, ,near Vienna,

signor to Deutsche Goldstalt vormals Roessler,

Austria, asund Silber Scheidean- Weissfrauen, Frankfort-on-the-Main,Germany Application June 14, 1932, Serial No.'617,161, and in GermanyOctober 2, 1931 2 Claims.

This invention relates to the continuous production of anhydrous ethylalcohol directly from mashes and the like.

In the specification of application for patent Serial No. 617,473, filedJune 15th, 1932, there has been described a process that enables thehigh boiling point impurities-especially the fusel oils-to be removedfrom raw spirit by treating this raw spirit with suitable dehydratingagents, especially salts or salt solutions, such I as solutions of thefatty acid salts of the alkalis and earth alkalis so that the ethylalcohol content in the vapor phase is increased to such an extent thatthe ethyl alcohol'distils off poor in water whilst the fusel oils remainbehind. As an especially suitable salt for this purpose, there wasrecommended in the specificationof the aforesaid application a mixtureof about 70 per cent. of potassium acetate and about 30 per cent. ofsodium acetate. It was also recommended in the specification of theaforesaid application, for the purpose of more effective dehydration,that the vapors of the alcohol to be purified pass through the saltsolutions or suspensions or are washed therewith in suitable devices,and finally it was recommended to enhancethis action of the saltsolutions or suspensions on the alcohol vapors by reducing the salts tothe anhydrous condition and employing absolute alcohol as solvent orsuspension agent for them so that, instead of an alcohol poor in water,anhydrous alcohol is distilled off free from high boiling pointimpurities, especially fusel oils.

It has now been found that the process described in the specification ofthe aforesaid application can beapplied, with great technical andeconomic success, to the obtaining of .raw spirit from mashes, worts,spent sulphite liquors and the like, and that for the carrying out ofthe process it is-suflicient to employ a comparatively simplearrangement of apparatus, which works with very favorable heat economy,owing to the fact that the spirit is not, as hitherto usual, brought tohigh concentrations-e. g. to 94% by weight-by distillationrequiring agreat deal of steam, but is subjectedin the distillation apparatusmerely to a preliminary concentration to relatively low strengthrequiring the expenditure of only moderate quantities of heat, whilstthe main work of concentration is transferred to' the dehydratingapparatus. Further, the heat that must be used up in thede-alcoholization and in the first concentration of the raw spirit isagain utilized to a very large extent.

Processes are already known that produce absolute alcohol directly frommashes in one operation. Inter alia, such a method of operation isproposed in French Patent No. 644,202, a saving of steam being obtainedin that method mainly in using up the heat contained in the vinasse orin the de-alcoholized spent liquors. However, in the case of this knownprocess, there is no saving in the proper sense of obviating theconsumption of heat, but merely a using up of existing heat. Such autilization of the heat contained in thevinasse or in the de-alcoholizedspent liquors is a saving only in the sense that it represents economyif this heat would otherwise be allowed to dissipate uselessly. This is,however, not the case 1 in works with modern equipment. The heatcontained in the vinasses or de-alcoholized spent liquors is of use infurther treatment, either in the inspissation of the vinasse or in itsworking upto crude potash; in other cases, this heat is used up for theproduction of hot water or for room heating. In contradistinction to theknown processes, the present invention does not use up existingquantities of heat, which could be quite as valuable in otherdirections, but involves actually a minimum consumption of heat, owingto the fact that the alcohol is not, as hitherto usual, concentrated tovery high degrees of strength in the rectification column, but isconcentrated by expenditure of substantially smaller consumption ofsteam to only moderate degrees of strength, whilst' the main work'in thedehydration of the alcohol is performed in the dehydrating apparatus inwhich the alcohol becomes absolute and the dehydration can be carriedout with asubstantially more favorable heat efiect.

In the process of the French Patent No. 644,202 the statement of priorart concerning the amount of steam required for the rectificationfollowed by dehydration of the alcohol when using the usual old methodsof concentration by distillation and 9 azeotropic dehydration is givenas 875 kgs. per hectolitre of absolute alcohol and the amount requiredfor distillation or rectification combined with dehydration into asingle operation with suitable apparatus is given as 700 kgs. perhectolitre.

According to the process described in the French patent it should bepossible to manage with 350 kgs. of steam. As already stated above, thissaving is essentially to be attributed to the very, large extent ofutilization of the vinasse heat. In contradistinction to this, thepresent invention enables one to manage with a consumption of steam ofless than 350' kgs. notwithstanding the conservation of the valuablevinasse heat. It the local conditions render it possible, the vinasseheat can be wholly or partially used for covering the heat requirement.The sald'consumption of heat of less than 350 kgs. is, accordingly. thenstill iurther reduced. X

The arrangement of apparatus according to the present invention forcarrying out the process of the application for patent Serial No.617,473, filed June 15, 1932 will now be described with reference to theaccompanying drawing The mash arrives through the pipe 1 and, for

the purpose of being prehe ted, first flows through the condenser 2. A!being preheated it enters at 3 the bottom portion of the'distilling andconcentrating column A. The co plete de alcoholizationoi the mash takesplace the bottom part oi. the column, so that the vinasse flows awaythrough the piped tree from volatile constituents. In the upper part ofthe column A the concentration or the vapor mixture takes place to suchan extent that an alcohol 0! about 60-90% strength is obtained which, inaddition to carrying off the low boiling point head products such asacetaldehyde, ethyl acetate and the like, carries with it all the fuseloils as impurities. This prodnet-is drawn off in the fluid conditionthrough the pipe 5 and is passed into the head products capacity or thelatter. A part of the alcohol- ..vapors evolved therein heats the columnB column B having the condensers 6, and '7. In this column the lowboiling head products, such as acetaldehyde, and low boiling esters,such as methyl and ethyl acetate, are separated oil as thoroughly aspossible. On the other hand, the iusel oils, as well as the greater partof the methyl alcohol that occurs, for example, in the treatment ofspent sulphite liquors, remain in the alcohol. The head products arecondensed in the condenser 8 and leave the apparatus through the pipe 9.The heating of the column B is eflected by means of the heating device0.

In order to complete the removal oi! the head products-thus, forexample, to destroy the last traces of esters or to remove traces ofacetaldehyde-which could subsequently have-a deleterious effect, byacidification, on the quality or the absolute alcohol obtained, theboilin in the heating device C .may be combined with a chemicaltreatment with lye. The whole or the alcohol flows through this heatingdevice C or Y stays therein for a length of time corresponding to thethrough the pipe lm'the main quantity corresponding to the throughput Iv: through pipe 11 into the dehydrating apparatus D.

The alcohol entering the dehydrating apparatus or column D in thecondition of vapor is washed with a solution or suspension of suitabledehydratlng salts in absolute alcohol. To this end, the aqueous saltsolution resulting from the dehydrating process is forcedby aliquid-raising pump12toaraisedreservoir13,iscompletelydehydratedinapanuandisnminmoltenconditionintoastirringvessell5inwhichitisdissolved inabsolute alcoholwhichisbranched oil through thepipe IG iromtheendproductotthecolumnD.Thisalcohollosaltsolutloncntersthetopotthe below could, mixed with watervapor, pass into the head products or, on distillation, contaminate thealcohol being distilled off, go into.

the residue accordingto their boiling point in the condition in whichthey are poor in, or tree from,

the pipe 191. From the top of water, and can be drawn oil, together withthe aqueoussalt solution and small quantities of alcohol remainingtherein, throlmh the pipe 20. In the small column E, further use is made01 this behavior of the iusel oils, that'are poor in water, tor thepurpose or completely separating them from the last traces of alcohol.This column E sends the last traces of spirit back into the column Dthrough the pipe 21, whilst the high-percentage lusel oils are drawn 0!!at a suitable height in the condition of vapor and passed through thepipe 22 to the condenser 23. From the body of the still of the column E,the com pletely de-alcohclized aqueous salt solution flows through thepipe 24 to the liquid-raising pump 12 already mentioned.- 1

By means or the mode oi operation described, it is possible to producepure absolute alcohol directly from a mash or other alcohol-containing,initial material in one operation and in a continuous process with aconsumption of steam that is I substantially smaller than that which hashitherto been necessary for the production of pure alcohol (94% byweight) that still contained water.

From the above description it is apparent that the process of purifyingand simultaneously completely dehydrating spirits directly from meshes,worts or fermented sulphite liquorscan be continuously carried out bydealcoholizing the meshes etc.,' then separating the first runnings andpartially concentrating the same and thereafter purifying and finallyconcentrating the al-- cohol in a dehydrating plant. Or it is alsowithin the purview of the invention to continuously sep-- arate ofi afirst running, then dealcoholize the residue from the first running andthen concen-' trate the alcohol vapors. Thereafter the alcohol may bepurified and dehydrated by means or a dehydrating medium dissolved inabsolute alcohol. Then the pure non-aqueous alcohol is collected andcooled and the dehydrating medium is also collected together with thehigher boiling impurities. The latter is dealcoholized so that the luseloil together with the remaining traces us I of alcohol in thedehydrating medium are drivenoi! and the alcohol obtained is returned tothe continuously from mashes, worts or spent sulphite 1m distillationfollowed by dehydration,

liquorsv by in series communication a distillation comprising column inwhich the concentration oi! the ethyl alcohol in the raw. material israised to from 80 to 90 per cent by weight, a second column into 14,5

which the head product oi. the first column is and. fromwhichacetaldehyde. ethyl acetate and similar readily volatile impuritiesare driven'oil, a dehydrating columnanilmeans to pass vapors from thesecond column to the dehydrating column in counter-current to analcoholic solution of dehydrating agent, means for condensingthe{aurified and dehydrated alcohol vapour passing out at the top of thedehydrating column, means for subjecting the liquor withdrawn from thefoot of the dehydrating column to a de-alcohoiizing action whereby theaqueous dehydrating agent is freed from remaining alcohol which isreturned to the dehydrating column and from fusel oil which is collectedseparately,

